Piston fob steam-engines



I PATBNTEDTOGT. 9, 186C. T. s. LA FRANCE.

PISTON.

HNI

UNITED STATES PATENT OFFICE.

TRUGKSON S. LA FRANCE, OF ELMIRA, NEW YORK.

PISTON FOR STEAM-ENGINES.

Specification of Letters Patent No. 30,328, dated October 9, 1860.

To all whom it may concern:

, and I hereby declare thatl the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, making part of this specification, in which" Figure l is a vertical or longitudinal section of the piston and rod. Fig. 2 a view of the front end of the piston with the fol lower removed. F ig. 3 a side view of the slotted screw rod g.

The letters of reference indicate the same parts in the different figures.

The nature of my improvements relate to that class of metallic pistons the packing of which is capable of being expanded or adjusted without the removal of the cylinder head.

The piston rod A consists of a hollow cylinder in which is a close fitting rod B, capable of being moved longitudinally. The piston is constructed with the back follower O, cast in one piece with the wings or spider D, to which the front follower E, is bolted.

F is the outer divided ring, and G the inner ring, which is divided into three segments.

The enlargement a, of the front end of the rod B, has three grooves the bottoms of which are planes inclined to the axis of the piston rod. Three radial studs H, upon each of which a screw thread is cut, pass through the spider and support strong springs I, which bear against the inside of the segmental ring G, and are held in position by the set nuts c. The inner ends of the studs I-I are formed with tenons which fit into the grooves Z), and rest upon the inclined bottoms of said grooves. The crosshead end of the rod B, has a slot d, into which a cross bar K is fitted, this bar also passes through elongated slots e, in the rod A. To each end of the bar K, screw rods f and g are attached, they pass through the flange L, which is secured to the rod A, they are held in position by the set nuts la. The rod f, is permanently attached to the bar K, but the rod g, has a slot through which the end of the bar K passes by which means it can be readily disengaged if required.

hen it becomes necessary to expand the packing the cross bar K, is drawn toward the cross head by means of the nuts and screw rods f and g. This moves the rod B, with its inclined planes, which by their action against the studs forces them outward thus increasing the pressure upon the springs I and expan ing the rings.

Vhen from wear of the piston and cylinder and continued repetition of the above operation, the set becomes exhausted, the inclined planes are brought to their original position and a new set is taken by forcing the springs outward by means ofthe nuts upon the screws of the studs H.

The piston above described possesses among other important advantages, that of capability of being expended and adjusted without involving the necessity of removing the cylinder head. The pistons of a locomotive can be regulated in one or two minutes at any stopping place, or even when moving slowly. The expansion, from the const-ruction and arrangement of the various parts is necessarily equal in every direction from the center, thus avoiding injurious friction. It frequently happens that the cylinder is bored slightly tapering, as I am enabled to adjust the piston in any part of the cylinder the important advantage is gained of setting out the piston to the smallest diameter of the bore. The above described means of renewing the set also presents a great advantage over all other pistons in use.

Having thus fully described my improvements, what I claim as my invention and desire to secure by Letters Patent is- 1. The combination of the hollow piston rod A with the rod B, when the said rod B,

In testimony whereof I have signed my name to this specification before tWo sub- 10I seribing Witnesses. Y Y Y T. S. LA FRANCE.

Witnesses :i f

CHAs. EVERETT,

W. DETRAY. 

